


Mutualism

by AndromedaPrime



Category: Transformers - All Media Types, Transformers: Prime
Genre: M/M, Oral Sex, Sticky Sexual Interfacing, Tribadism, past Megatron/Optimus Prime - Freeform
Language: English
Status: Completed
Published: 2015-09-25
Updated: 2015-09-25
Packaged: 2018-04-23 08:24:46
Rating: Mature
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 3,318
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/4869983
Author URL: https://archiveofourown.org/users/AndromedaPrime/pseuds/AndromedaPrime
Summary: <blockquote class="userstuff">
              <p>A nervous Ultra Magnus and a fairly confident, talented Optimus Prime come together in wonderful ways.</p>
            </blockquote>





	Mutualism

**Author's Note:**

> I'd been left with a mighty need for a semi-truck pile-on for a while. What I prompted to myself: Magnus needs release and goes to Optimus for help. This is the result from that prompt.
> 
> Thanks to my friends for encouraging me in this endeavor X3

“Are you certain about this?”

Bright blue optics looked at him, and the voice that came with said optics chuckled quietly. “First you said you wanted this, no – _needed this,_ and then you asked me. And I agreed to it. Now you’re having doubts?”

“I’m doubting that you actually want to do this, Optimus.”

“I am. Now my question is whether or not you still have the urge to do this.”

“I do.”

“Then with the issue of mutual consent settled,” Magnus felt a servo gently press against his chassis, a silent order for him to lie back on the berth that he obeyed, “please allow me.”

Ultra Magnus closed his optics and did his best to relax his frame. Eons had passed since he had allowed anyone to come close to him in this fashion, so the servos gently parting his legs and coming to stroke his inner thighs were a foreign sensation. Part of his processor interpreted the motions as pleasurable, while the other half insisted that he close his legs and get out, and to tell the Prime that he had changed his mind. Optimus wouldn’t be mad, after all.

No. He wanted this.

A soft laugh from somewhere around his hips. “You know, it helps greatly if both partners are relaxed, Magnus.”

“I know. It has been a long time, Optimus. Forgive me for being…”

“There is nothing to forgive, Ultra Magnus. You have done nothing wrong.”

The sound of the Prime’s voice soothed his frazzled and worried neural net some, but admittedly not by a lot. Magnus huffed and repeated the Prime’s words in his processor. He had done nothing wrong. He would be in good servos.

The Commander of the Wreckers jolted and his intakes hitched when he felt blunt-tipped digits stroke the lining of his interfacing panel at the apex of his thighs. He opened his optics and slowly curled his servos into fists, resting them on the surface of the berth.

“Should at any point you want to stop, say so and I will stop.”

Magnus nodded. He was in good servos, he told himself.

Lipplates pressed against the smooth surface of his inner thigh, and he had to resist the urge to clamp his legs closed together. Doing so would have dented the Prime’s helm in and given him a helm-ache of unparalleled proportions.

Optimus seemed to sense his discomfort. The Prime hummed against his thigh, the vibrations of the red and blue mech’s vocalizer shooting straight into the deep center of his abdomen. The Commander’s vents hitched, his servos sought to dig themselves further into the metallic and unmalleable surface of the berth. Primus, what were these particular sensations and why were they so very, how to say it, amazing?

He was not used to amazing sensations such as this. This was wartime, he was not supposed to know these feelings, he was most certainly not supposed to have asked the Prime to relieve him of stress in this fashion, and he most certainly was not supposed to have said Prime of Cybertron lightly mouthing at his inner thighs.

Magnus could only think of the scandal that might arise if the Commander and the Prime were caught right now. Such a thing was not illegal (and he would know, as he had designed the manual for Autobot regulations at the outbreak of combat), but there would be a serious conflict of interest within the ranks if this were to become public knowledge.

His processor quickly became distracted - there was a momentary feeling of loss when the lipplates moved away from his armor plating, which quickly subsided when Optimus pressed his lipplates to his other thigh. The feeling of fire in his deep abdomen returned but the sudden resurgence troubled Magnus. He tensed up and tried to speak, saying, “Ah-Optimus, I…”, but his body language spoke for him.

The Prime ceased his ministrations and looked up at Magnus, staring into his optics. “Do you want me to stop?”

A moment’s thought. Magnus shook his helm. If it were possible he would have already combusted in shame. “No, I just… this is new.”

Optimus rubbed circles on the blue mech’s silver thighs with his digits as he held them in his servos. He wouldn’t admit it just then, but he got some pleasure from the minute quaking he could feel from Magnus’s legs being held up and apart. “I would have assumed that you and your former partner might have had some experience in this.”

Magnus felt his spark clench into itself, a sensation he didn’t know was possible until he felt it. He looked away from Optimus’s prying gaze. “No. He and I rarely interfaced and even when we did so, he was only interested in doing the bare minimum, which meant he would rut in me until he’d had his fill, then fall into recharge.”

The Prime stopped rubbing circles on Magnus’s thighs and looked at the blue mech with an expression of what seemed to be a mix of compassion and pity. The look made Magnus’s spark drop further and he was about to turn his gaze away and ask if Optimus wanted to keep going when he felt servos gently cup his helm and lipplates press against his.

The kiss was gentle, the embodiment of the Prime himself. Magnus felt himself truly relax for the first time in this entire process.

Much to his chagrin, Optimus soon broke the kiss, but then those lipplates that once been on his came to press against one of his audio receptors. It was instinct that made Ultra Magnus cup the back of Optimus Prime’s helm with his servo, holding the red mech close.

“I’m sorry that you weren’t appreciated as one should be,” Optimus whispered into his audio receptor. Magnus felt the Prime go tense against him. A slightly horrified tone seeped into his voice when he asked Magnus, “Did your previous… did he force himself onto you?”

“What?” The Commander’s processor reeled at the question. He composed himself enough mentally to respond, “No, Optimus, no.” Magnus shook his helm. “But our lack of regular intimacy has left me without knowledge of what to do and how I should feel in these instances. I am merely inexperienced.”

Optimus backed up, which made Magnus release the grip he had on the Prime’s helm, and stared at the blue mech. Both mechs held gazes for a nanoklik before Optimus leaned in again and lightly pressed his lipplates against Magnus’s. The blue mech savored the liplock for the brief time it lasted, and then Optimus began kissing his way down the strong and sturdy frame.

His neck cables tensed when the Prime passed his lipplates over them, peppering them with kisses. When Optimus trailed his kisses down his chassis, his spark fluttered as Optimus reached the part of his chassis that protected said spark.

“I can feel your spark pulsing, Magnus,” Optimus said lightly, in an amused manner. “I take it you’re enjoying this?”

.-.-.

There was no verbal answer, but Optimus looked up and saw the relieved and – dare he say it this prematurely? – _blissful_ expression on the Wrecker Commander’s faceplates. Optimus wanted to kiss him again, remind him that he was worth so much and deserved to be cherished and appreciated, but that would be him overstepping his boundaries at the moment.

 _Funny_ , the Prime thought, as he continued making his way down the blue and red mech’s frame, taking note of each seam where the plates that made up Ultra Magnus, the fearsome Commander of the Wreckers, were. _Funny_ , he thought, as he reached the pelvic plates and kissed them hard, eliciting a moan and an arch of hips from Magnus, _that I would overstep my boundaries to tell him he is worthy, when I am about to be intimate with him._

His digits went back to stroking the lining of the interfacing panel at the apex of Magnus’s thighs, and Optimus again savored the minute shakes of stimulated legs. “Open for me, Magnus.”

Magnus’s optical ridges furrowed as if in thought, and a moment later he surrendered.

.-.-.

The cool air of the berthroom passed over his valve that – Primus frag it – was already leaking. A tender digit came into contact with the puffed edges, stroking along the lining and spreading lubricant around.

He could have sworn he heard Optimus murmur “Beautiful” from between his legs.

The blunt-tipped and tender digit swiped upwards along the rim of his valve and came to circle and swipe across-

Magnus would have jolted if it weren’t for Optimus holding onto his leg with one servo and pressing some of his own weight down on the other leg with his arm. That was a strange sensation. He’d known it was there all along, hidden in the folds of his valve, but he had never put it to use. So that was what it was used for?

“How…” Magnus trailed off a moment and leaned his helm back, his vents stuttering at the wholly foreign and wholly amazing sensation of his anterior node being teased so wonderfully, “how did you learn to do this?”

From between his legs, Optimus replied without missing a beat: “Megatronus and Orion Pax were _very_ creative.”

Magnus thought of the little data clerk he had seen in photos before his transformation into Optimus Prime, and how the great gladiator from Kaon must have looked while coming undone underneath the little data clerk’s skillful digits. He himself was about to come undone, but he didn’t want to, because that would mean that Optimus would go away.

No. He was in good servos, he reminded himself again.

.-.-.

Optimus took the anterior node between his thumb and fore-digit, pinching it lightly (and eliciting a soft gasp of mixed pain and pleasure from the blue and red mech) before he went back to circling his digits around the rim of the valve. Slowly, carefully, he introduced one digit into the wetness of Magnus’s valve, and then promptly found himself unable to move it.

“Magnus,” he chuckled, withdrawing the digit after some struggle, “relax.”

“I’m sorry, Optimus. I don’t think I’ve ever had a digit down in there, before.”

“It _is_ smaller than a standard spike on a standard Cybertronian.”

“But it is more stiff. Therefore it is capable of causing some damage.”

“Point taken.” So no digits for now. That was fine. He could attempt to introduce them later on, if Magnus wished for both a later on and to be introduced to such a method.

“Here, allow me – can you move up?” Optimus posed the question and helped Magnus to shift partway up on the berth, making sure that Magnus was comfortable before he laid himself on the berth as well, as much as he was able to with the limited space. He traced one digit along a puffed valve edge. “I remember the first instance this was done to me, it was such a foreign sensation. Please refrain from kicking me in the faceplates.”

.-.-.

Magnus’s processor conjured an image of Orion Pax kicking Megatronus in the faceplates. He found it funnier than it should have been.

The smooth surface of a glossa swiped against his valve and the image went away, replaced by something abstract that he could only interpret as being shock. Magnus tensed, and then remembered Optimus’s words to relax, and he did so.

Oh Primus the feeling of something so smooth and very wet against his valve felt… he couldn’t put it into words. He quite honestly struggled to find a way to put it into words other than pleasurable and shocking.

Digits pressed against the area surrounding the puffed folds of his valve, agile glossa licking along the rim, retracing the path that the Prime’s digits had taken, before delving inside, and the way that Optimus’s glossa pressed against sensitive nodes and clusters that he didn’t even know were there made his world invert. He reached out and wrapped a servo around the back of the Prime’s helm, steadying himself both physically and mentally as Optimus continued his ministrations.

Magnus felt Optimus’s faceplates press further into his valve, nasal ridge scraping against his stimulated anterior node, glossa licking that much more deeply into his frame. Before he could stop himself he began rolling his hips into the direction of the stimulation, grinding his pelvic span against Optimus’s faceplates.

The Prime laughed, and it felt amazing against his valve, and that was all that was needed to finally bring the Commander of the Wreckers to a full, hard, and long overdue overload. Magnus cried out and tried to stifle the cry by placing a servo over his mouth, but Optimus still heard it at full-volume. He pressed Optimus’s faceplates to the apex of his thighs, and the Prime was _still_ licking and sucking, teasing him and prolonging his overload as much as he was able to.

He rode the overload as long as it lasted, finally coming down from his euphoric high, and had enough presence of processor to look down at the Prime. Blue optics stared at him, a mouth still on him and painted with viscous fluids. When Magnus came down from his high he realized what had caused the fluid buildup on Prime’s faceplates and was immediately horrified. He released his grip on the Prime’s helm. “Let me… Primus, I’m sorry Optimus. I’ll go get a cleaning cloth.”

In response, the Prime wiped the back of a servo across his faceplates. “There is no need for that, Magnus.” He put his digits to the other mech’s valve again, and Magnus tilted his helm back and his intakes hitched once more, calipers clenching in his valve. His legs quaked in response.

Warm air vented across the surface of his valve again as Optimus put his mouth there again, kissing the folds and swiping his glossa along the surface of the anterior node. All of the Prime’s frame seemed to be overheating – the temperature of the other mech’s frame jolted something in Magnus’s processor, and he realized that Optimus hadn’t had release yet.

He reached down and placed a servo on the side of the Prime’s helm. Optimus looked up at him.

“Optimus, you haven’t… overloaded, have you?”

The Prime stopped his ministrations. That was all the answer that Magnus needed.

“Here, let me,” Magnus grabbed Optimus by a piece of his chassis armor and coaxed him upward on the berth until they were face-to-face. He almost shyly pressed his lipplates to Optimus’s before he rolled them over and placed his servo on the Prime’s still-closed panel. He was met with a very, very hot panel. Traces of lubricant were present at the seams.

Optimus needed no further coaxing, as the touch of the other mech’s servo prompted him to open it up.

Magnus marveled that Optimus had so much lubricant held back. The Prime hadn’t given any indication that he had been left with a need for release.

The image of the Prime between his legs, the sensation of a glossa in and on his valve, swiping over his anterior node, were still fresh in his memory. Ultra Magnus tried to put this to use by nudging apart the folds of the Prime’s valve with his nasal ridge, flicking the tip of his glossa over the anterior node, tasting the lubricant gathered there.

Above him, Optimus moaned softly. Optimus was relaxed during this process, a stark contrast to how Magnus had been tensed up and had been very responsive to these acts done upon him. Magnus took the moan as a sign that he was doing well so far, and he continued exploring the Prime with his glossa. He slipped his servos under the Prime’s thighs, holding them in his palms as he delved deep into the Prime’s valve.

Little sparks came into contact with his glossa, electric discharge along with the liquid lubricant that coated the walls. Magnus swiped his glossa around the clenching passage, which made the Prime’s vents stutter. He pressed his faceplates to Optimus’s valve and began licking all over and suckling, lost in the heady scent of lubricant and wondering just how long he could keep doing this until he made Optimus Prime come undone, just as he had come undone.

Strong thighs came close to clamping around his helm but the owner of said thighs stopped. “ _M-Magnus_ , not so fast,” Optimus managed to say, placing a servo on the top of Magnus’s helm and gasping. The Wrecker Commander pulled back, embarrassed.

“I’m sorry, Optimus.”

“Don’t be,” Optimus rasped out, optics closed. He opened them and looked at the blue mech, making a motion with his servo for Magnus to come to him. Magnus did so, resting his forehelm against Optimus’s. The Prime touched his cheekplate with a gentle servo. “It takes practice. I did not learn my methods overnight.”

Magnus inhaled and exvented. “I am not used to failing, Optimus Prime.”

“This is not failure. You merely need practice, which I am willing to give you more of if you wish it.”

The way the Prime looked at Magnus made him want to laugh. Who would have thought that the great Optimus Prime would have such sultry berthroom optics?

Magnus nodded once. Optimus smiled and brought his helm down to kiss him.

“Here, let me,” Optimus murmured as he pulled his legs out from underneath Magnus’s weight and wrapped them around the other mech, drawing him closer. Magnus was about to ask what Optimus was doing until their valves touched.

“Did you ever ride your previous partner in this manner, valve on spike?”

It was hard for the Commander of the Wreckers to gather his thoughts – his valve was stimulated again, and he could feel a fresh gush of lubricant sliding down his calipers. He managed to gather his thoughts, however, and nodded in confirmation.

“Then it is the same concept.” As if to prove a point, Optimus arched his hips up into Magnus, and _oh Primus and all that was sacred to the Primes,_ the charge that leapt through Magnus’s interface array felt divine. Magnus began thrusting against the valve, panting with all his effort, and looked to see that the Prime had his helm thrown back, servo placed over his faceplates, loud and obscene moan echoing in the berthroom.

Their interface arrays scraped and thrust against each other, sending waves of pleasure through both of their frames. Magnus couldn’t help but think that Optimus looked beautiful, now that the Prime was looking directly at him with mouth open and chassis heaving, optics dimmed to a dark blue. He couldn't see what he himself looked like, but he hoped he didn't look like a fool.

Reaching between them, Magnus found the Prime’s anterior node and began rubbing a digit across it in tune to their thrusts, and Prime shouted far louder than Magnus would have thought possible outside of a battlefield.

“M-M-Magnus!” Optimus’s optics were dark, wild, the Prime having lost all sense of control in his overload.

A gush of lubricant splashed against his array, the electric sparks triggering his second overload of the night. Magnus gasped and kept riding against the Prime’s valve until he found himself laying on the Prime’s chassis, helm under Optimus’s, held in a protective embrace.

The Prime quietly traced circles on the Commander’s helm, humming quietly to himself. Magnus wondered if Orion Pax had done this after every interfacing session he'd had with Megatronus. He shunted the thought aside, refusing to give the leader of the enemy any further thought.

Magnus looked at Optimus and cleared his vocalizer. “Thank you.”

Optimus looked at Magnus. “I am happy to oblige. Does this mean that you would like further instruction?”

There was no further thought to be had. Magnus nodded, and he smiled against Optimus’s lipplates when the Prime drew him in for another kiss.


End file.
